Press for drawing sheet metal



Feb. 23, 1932. C, 1 RHODES 1,846,610

. PRESS FOR DRAWING SHEET METAL .Filed March 2e, 1951 ffy XMCDQM; w,

and upon which upon which is Patented Feb. 23, 1932 UNlrEDsrATEs PATENT oFFicE CHARLES JOSEPH RHODES, OFWAKEFIELD, ENGLAND PRESS FOR DRAWING'SHEET METAL Application iiled March26, 1,931,v SreiialNo. 525,413, and in Great Britain December 24, 1930.

Thisinvention relates to presses for drawing sheet metal,` and refers to presses of the kind in which', in orderto effect deep drawing, the centre block of the lower vdie is caused to `inove upwards during the downward movement of the upper die, this movement beingeected by mounting the said block upon a rod actuated by levers operably cons .c nected with the even pressure table.

In order to avoid damage to the metal or creasing due to variation of the pressure eX- erted by the die upon the metal during the drawing operation, a spring was provided, arranged to act upon the even pressure table in a manner such thatthe above objections were avoided. Y Provision was made whereby theresistance of the spring could be regulated. For certain practical reasons the use of a spring in cases where very deep drawing isrequired, is not desirable.

Theipre'sent invention hasforits objectV certain improvements whereby the usev of a springfor the purpose of varying the pres;

sureis dispensed with'.

According to the present f invention, weights are employed, so arranged as toV adi just the resistance to the the die upon the metal.

ter understood, drawings are appendedin which:--V

. the present improvements applied thereto.V 35

Fig. 2 is a view showing a modification.'

Fig. 3 is a sectional view showing a certain detail., Y Y

Referring to Fig. 1 ofthe accompanying drawings, in which only such parts are shown 4()v as are necessary for the proper understanding of the invention, 1 indicates a portion of the frame of the machine at the upper end of which is provided the table-indicated by 2, table is secured a body 3 5 carried upon a crankoperated ram 6, the disc to be acted upon is cut from the sheet.

7 indicates a pressure or draw ring disposed wthin the die 4, and supported by pins pressureexerted by a short rack In order that the invention may beV the het` mounted :the lower die 4, whereby in combination with the upperdie rlhe table 10 is perforated for the free passage of a tubular rod 11,

which is supported its upper end, by

means of a lange 11a,

within a stepped bush 11b, which in turn is similarly supported within the body 3, the said rod at bracket comprising an upper member hav ing upon its under surface and'at each endV a pair of downwardly extending lugs such as 18. v

14 indicate nut-s or collars disposed upon the lower end of the rod 11 and arranged one upon each side of the upper member of the bracket to prevent movement of the said bracket longitudinally of the rod.V

Formed upon the underside and at each endof Vthe table 10 is a pair of lugs such as 15 which are bored to form bearings for spin,- dles 16 upon each vof which is pivotally` 'mounted the upper end of a downwardly eX- te'nding bar 17.

`Each of the bars 17 has kupon its outer face and approximatelyin the centre of its length,` 18, a similar rack indicated by 19 being provided upon the inner surface,` extending upwards from the lower end thereof. Y

The respective pairs of lugs 13, which as liereinbefore described are formed upon the underside of the table 10, are each bored to form bearings for a spindle 20,upon each of which spindles is mounted a pinion 21 which engages with the adjacentrack 19, the other sine of each of the said a rack 22 provided upon a body 23 disposed between the pinions and secured by means of nuts 23a upon the lower end of a rod 24 which freely passes upwardly through the bore of the rod 11, and is screwed at its uppler end into the foriningblock 25.

Formed integral with the bracket 12 at each end thereof, and extending horizontally therefrom is a pair of lugs such as 26,the said lugs being so arranged that there is one upon therear and forward sides of each bar 17. Each of the pairs of lugs 26 extend outwardly pinions engaging with I somewhat beyond the outer faces of the bars 17, and are bored at their outer ends to form bearings for spindles 27 upon each of which is pivoted a lever Q8.

rIhe inner end of each of the levers 28 is provided with a toothed sector 28a which engages with the raclr 18 of the respective bars 17 and the outer end of each of the said levers is provided with a weight 29 which is adjustable longitudinally thereof and may be clamped in the desired position by means of a clamping bolt 30.

The aforementioned spindles Q0 are of such length that they each project outwardly somewhat beyond their bearings at each end. Mounted upon the respective rear and forward ends of the spindles Q0 is a horizontally disposed body 31 which extends at its ends somewhat beyond the outer side faces of the bars 17, the arrangement being such that the said rods each extend between ythe said bodies carried in bearings formed at the outer ends of the bodies 31 and extendingl therebetween at each end is a spindle 3Q upon which is mounted a roller 33, which engages with the face of the adjacent bar 17 to thus maintain the rack 19 in engagement with the respective pinion 21.

Instead of arranging for the weights to be adjustable, they may be fixed, as shown in Fig. 2, in which case provision is made for damping their effect.

The means for damping the effect of the weights comprises plates l 3 of suitable material carried upon shoes 34 adjusfably mounted by means of pins 35 upon bodies 36 mounted upon the respective spindles 3Q, as shown in Figs. 2 and 3, clamping bolts 37 being provided within the bodies 36 whereby the shoes may be moved to bring the plates 33 into frictional contact with the bars 17.

38 indicates an' ejector whereby as the die 5 moves upward the article is ejected from the said die. The operation of the machine is as follows:-

As the ram 6 descends, the upper die 5 causes the draw ring 7 to be depressed, this motion being transmitted through the pins S to the table 10 causes the same to also descend together with the bars 17. rIhis downward movement of the bars 17 causes the rack 19 to rotate the pinions 21, which in turn transmit through the racks 22 an upward movement to the rod 24, which is thus transmitted to the forming block Q5, the racks 1S at the same time acting upon the toothed sectors 28a to cause the weights 29 upon the outer ends of the levers 28 to be swung upwardly.

It is to be noted that in addition to ensuring an even and constant pressure between the'two dies, the weight 29 also acts to return the moving parts 10 and 17 and also parts of the bottom die. In the event, however, of the return of the parts being prevented, by

slacking, there are provided vertically disposed rods 39 secured at their upper ends by means of nuts 40 to lu gs 41 formed integral with the ram 6 and arranged in pairs one upon each side thereof, the said rods freely passing through the table 2 and through lugs 42 formed upon each side of the table 10, nuts 43 being provided upon the lower ends of the rods whereby when the ram moves upward these nuts engage the undersides of the lugs 42, and thus ensure that the table 10 is returned to its normal or uppermost position.

Claims:

1. In a press for sheet metal a movable die, a fixed die, a movable block in said fixed die, a pressure table, a fixed body, levers upon said body operatively associated with said pressure table, weights upon said levers, means operatively connectingr the pressure table with said movable member of the fixed die in a manner such that the weights act to provide a constant resistance to the pressure of the tool and to return the parts after operation.

2. In a press for sheet metal, a movable die, a fixed die, a movable block in said fixed die, a pressure table, a fixed body, levers upon said body operatively associated with said pressure table, weights upon said levers, means operatively connecting the pressure table with said movable member of the fixed die in a manner such that the weights act to provide a constant resistance to the pressure of the tool and to return the parts after operation, and means for regulating the effect of said weights.

3. In a press for sheet metal, a movable die, a fixed die, a movable block in said fixed die, a rod connected to said block, a fixed body, toothed sectors mounted on said body levers associated with said sectors, weights upon said levers, a pressure table, members carried by the pressure table, racks on said members engaging the sectors, other means upon said members operatively engaging the rod of the movable member of the fixed die, said weights acting to provide a constant resistance to the pressure of the tool and to return the parts after operation, and means for regulating the effect of said weights.

4. In a press for sheet metal, a movable die, a fixed die, a movable block in said fixed die, a rod connected to said block, a fixed body, toothed sectors mounted on said body levers associated with said sectors, weights upon said levers, a pressure table, members carried by the pressure table, and engaging the sectors, pinions upon said body, other racks upon the members carried by the even pressure table engaging said pinions, racks upon the rod of the movable member of the fixed die engaged by said pinions.

5. In a press for sheet metal, a movable die, a fixed die, a movable block in said fixed die,

a rod connected to said block, a fixed body, toothed sec-tors mounted on said body, levers associated with said sectors, weights adjustable upon said levers, a pressure table, members carried by the pressure table, and engaging the sectors, pinions upon said body, other racks upon the members carried by the even pressure table engaging said pinions, racks upon the rod of the movable member of the liXed die engaged by said pinions.

6. In a press for sheet metal, a movable die, a xed die, a movable block in said fixed die, a rod connected to said block, a fixed body, toothed sectors mounted on said body, levers associated With said sectors, Weights fixed to said levers, a pressure table, members carried by the pressure table, and engaging the sec-- tors, pinions upon said body, other racks upon the members carried by the even pres- 2o sure table engaging said pinions, racks upon the rod of the movable member of the fixed die engaged by said pinions, and brakesfor regulating the effect of the Weights.

In testimony whereof I ailix my signature. .3 CHARLES JOSEPH RHODES. 

